(First Aspect)
Conventionally, delaminatable containers are known that are provided with a container body having an outer shell and an inner bag, the inner bag delaminating from the outer shell and being shrunk with a decrease in the contents, and a check valve to regulate entrance and exit of air between an external space of the container body and an intermediate space between the outer shell and the inner bag (e.g., PTLs and 2).
In PTL 1, a cap mounted to a mouth of the container body has a built-in valve.
In PTL 2, a valve is provided inside a main portion of the outer shell.
(Second Aspect)
Conventionally, delaminatable containers are known that inhibit entrance of air inside the container by an inner layer delaminated from an outer layer and shrunk with a decrease in the contents (e.g., PTL 3). Such delaminatable container is provided with an inner bag composed of the inner layer and an outer shell composed of the outer layer.
In PTL 3, the presence of an aperture in the inner bag is inspected based on whether or not, by supplying air into the inner bag, the pressure in the inner bag reaches a predetermined value after a predetermined time period.
(Third Aspect)
Conventionally, delaminatable containers are known that inhibit entrance of air inside the container by an inner layer delaminated from an outer layer and shrunk with a decrease in the contents (e.g., PTL 4). Such delaminatable container is provided with an inner bag composed of the inner layer and an outer shell composed of the outer layer.
The outer shell of the delaminatable container is provided with a fresh air inlet that enables shrinkage of the inner bag. The fresh air inlet is formed normally using a punch cutter or the like from outside the container where it is not easy to securely form a fresh air inlet in the outer shell without damaging the inner bag.